FunctionExampleLegal effect
ExtensionLand up to a wallThe boundary object is excluded
Exclusion / delimitationWashing to the elbowsThe boundary can be included
DeferralDivorce after a monthThe effect arises later
Extension carries an existing scope to a limit; exclusion narrows a potentially broader scope; deferral postpones the very occurrence of a legal effect.
This is why ila cannot be interpreted by a single mechanical rule about endpoint inclusion in all contexts.